It isn’t the book. You’ve read Simulacrum countless times over the years, and each time, you find something that you had noticed before (you like to think it wasn’t there at all). It is a massive compilation of whimsically metaphysical stories, essays, and an otherwise general potpourri of literature. You’ve tried to get others to read it, but between the page length and the difficulty of obtaining a copy, you’re the only one you know who has ever read it. This copy was printed with a hundred plus blank pages, which you use to write any particularly good thoughts you have.
While you carrying the doorstopper itself is somewhat irregular, after you acquired the e-book and pocket version (which nobody else seems to be willing/able to find), it isn’t worth remarking upon.